Adaptive reactivation of phases deactivated by phase-shedding in multi-phase voltage regulators

A multi-phase power supply voltage regulator configured to function at a nominal switching frequency, comprising:

• a plural number of phases;
• a variable frequency controller configured to set the nominal switching frequency;
• and
• a phase switching controller configured to switch off one or more of the phases to optimize energy efficiency at relatively low load conditions of operation, the controller including:
• a sensor configured to sense an instantaneous current absorbed by a load;
• a first comparator configured to determine a band of output current levels among a plurality of bands corresponding to the number of phases of the multi-phase power supply voltage regulator;
• a frequency detector configured to detect an equivalent switching frequency given by a product of said nominal switching frequency by a number of the phases that are active, the frequency detector being configured to update the detected equivalent switching frequency at every beat of a clock signal;
• a second comparator configured to compare the updated detected equivalent switching frequency with a plurality of thresholds and determine a band of equivalent switching frequency values, among said plurality of thresholds, to which the updated detected equivalent switching frequency belongs;
• and
• a combinatory logic circuit block configured to logically combine said determined band of output current levels and the determined band of equivalent switching frequency values, and switch on one or more stand-by phases of the plurality of phases in response to a load increase transient.

A control system configured to control a multi-phase power supply voltage regulator that includes a plural number of phases;

• a variable frequency controller configured to set a nominal switching frequency of the multi-phase power supply voltage regulator;
• and
• a phase switching controller configured to switch off one or more of the phases to optimize energy efficiency at relatively low load conditions of operation, the controller including:
• a sensor configured to sense an instantaneous current absorbed by a load;
• a first comparator configured to determine a band of output current levels among a plurality of bands corresponding to the number of phases of the multi-phase power supply voltage regulator;
• a frequency detector configured to detect an equivalent switching frequency given by a product of said nominal switching frequency by a number of the phases that are active, the frequency detector being configured to update the detected equivalent switching frequency at every beat of a clock signal;
• a second comparator configured to compare the updated detected equivalent switching frequency with a plurality of thresholds and determine a band of equivalent switching frequency values, among said plurality of thresholds, to which the updated detected equivalent switching frequency belongs;
• and
• a combinatory logic circuit block configured to logically combine said determined band of output current levels and the determined band of equivalent switching frequency values, and switch on one or more stand-by phases of the plurality of phases in response to a load increase transient.